Plunger pumps utilize positive displacement where a seal which is high pressure is stationary, allowing a cylindrical plunger which is smooth to slide within the seal. This means that they can be used at pressures which are much higher, and as such are regularly used to transfer industrial or municipal sewage.
How These Pumps Function
Plunger style pumps are similar to piston pumps in that they are reciprocating, but use a plunger rather than a piston for the movement of objects through the cylindrical chamber. The plunger will be actuated by a drive that is either electric, pneumatic, steam powered or hydraulic. The pump will make use of the crank mechanism to produce motion which is reciprocating, and which occurs on an axis. This then creates pressure within the cylinder or barrel so that gas is forced into the pump.
The chamber pressure will cause valve actuation, for both the discharge or suction points. As a consequence, plunger style pumps are preferred in applications that involve 1,000 up to 30,000 psi. The volume for the discharged fluid is identical to the plunger’s area, multiplied by the length of its stroke. The total capacity of the pump may be calculated with its area, along with the length of the stroke, drive speed and the amount of plungers. The power required from a drive will be proportional to the pump’s capacity and pressure.
The Importance Of Seals
Seals play an important role in these pumps, as they separate the media which is pumped from power fluid. The stuffing box will typically be utilized so that the joint between the plunger and vessel in which the media will be moved is sealed. The stuffing box might consist of seal rings, bushings or a gland. The component materials selected for these pumps are chosen based on their ability to handle wear, as well as the manner in which they will contact the media. The most popular materials include nickel alloy, brass, iron, bronze and stainless steel.
For instance, a plunger style pump that is used for oil or general service will typically use a plunger or cylinder made from iron. The suction valves, discharge valves, and the plunger itself will have contact with any media that is being moved, and the choice of material will be based on it. In certain applications which require plunger style pumps that are continuous duty, solid ceramic may be chosen as a material, but will not be in cases where the transferred media involves fluids which are highly acidic.
Choosing The Correct Pump
Most of these pumps are constructed with hard ceramic, which is popular due to its great durability and wear resistance. Choosing the correct pump for a pressure washer or other applications is very important. Different pumps have distinct applications where they perform best. Plunger style pumps are most optimal for tasks that require high pressure, much higher than is possible with piston pumps.
Talk to us today if you need help in selecting the right plunger pump for your specific application.